1. Field of the Invention
The present invention relates to a portable terminal device that carries out data communication via a mobile telephone terminal device. More particularly, the present invention relates to a portable terminal device that will be automatically turned on even if the power is turned off in the event of power being supplied to a mobile telephone terminal device.
2. Description of the Background Art
A portable terminal device that carries out data communication via a mobile telephone terminal device such as the PHS (Personal Handy Phone System) or PDC (Personal Digital Cellular) is becoming more popular than ever. By virtue of such portable terminal devices, the user can carry out data communication no matter where he/she is without any particular communication facility as long as communication via a mobile telephone terminal is possible.
Communication using such a portable terminal device is commenced generally by the procedure set forth in the following. First, the mobile telephone terminal device is connected with the portable terminal device. The power of the mobile telephone terminal device and the power of the portable terminal device are turned on. Communication software is activated on the portable terminal device by operating a mechanical key or by operating an icon displayed electronically. Upon completion of the series of operation, the portable terminal device can initiate data communication. This portable terminal device is referred to as the first conventional art hereinafter.
The technique of automatically turning on the power of a facsimile apparatus when commencing facsimile reception is disclosed in Japanese Patent Laying-Open No. 5-95463 as one type of data communication. According to this publication, the facsimile apparatus includes a circuit that detects the status of the telephone line. Upon detection of a call by the circuit that detects the status of the telephone line, the power of the facsimile device is turned on to initiate facsimile reception. This art is referred to as the second conventional art hereinafter.
According to the portable terminal device of the first conventional art, an operation of turning on the power is required to initiate the operation for data communication. In order to activate the communication software, the mechanical or electronical key provided at the portable terminal device must be manipulated or the process of manipulating the icon displayed on a display device by means of software must be carried out.
In general, a portable terminal device is mainly used other than at home. Now that electronic mail is so common, more and more users will receive electronic mail even when he/she is out if there is some time to spare. This often occurs when the portable terminal device is used in an area of limited space such as in an automobile or on a train. Then, even a desk cannot be used. Connecting a mobile telephone terminal device with a portable terminal device is not so easy under such an environment. Furthermore, the operation of turning on the power of each device and the operation to activate the communication software is even more difficult. The user may abandon the task of communication or be prevented from carrying out the operation properly. These problems should be solved.
The second conventional art is directed to save the power consumed by the facsimile device fixedly connected to the telephone line and is oriented to only the case of reception. The portable terminal device is not always connected to the telephone terminal in general. Furthermore, the portable terminal device will often carry out transmission in the data communication process. Therefore, the second conventional art cannot be applied to data communication based on a portable terminal device.
In view of the foregoing, an object of the present invention is to provide a portable terminal device that can help users carry out data communication without difficulty even in an environment where the operation of the portable terminal device is not easy.
Another object of the present invention is to provide a portable terminal device that requires less task in initiating data communication.
A further object of the present invention is to provide a portable terminal device that, when used connected to a mobile telephone terminal device, has its power turned on upon power-on of the mobile telephone terminal device.
Still another object of the present invention is to provide a portable terminal device that, when used connected to a mobile telephone terminal device, has preparation of data communication automatically effected upon power-on of the mobile telephone terminal device.
A still further object of the present invention is to provide a portable terminal device that requires less task in ending data communication.
Yet a further object of the present invention is to provide a portable terminal device that can specify the power-on status of the portable terminal device after data communication ends.
According to an aspect of the present invention, a portable terminal device includes a connector to be connected to a mobile telephone terminal device that provides a first signal that changes its status of output depending upon whether power is turned on or not, a power-on detection device connected to the connector, a power supply circuit under control of the power-on detection device, and a data communication device receiving power supply from the power supply circuit, and under control of the output of the power-on detection device.
Preferably, the data communication device includes a processor that activates system software when power supply is initiated from the power supply circuit. The system software responds to an output of the power-on detection device to activate communication software for data communication. The system software can activate an application program that uses the communication software in response to the output of the power-on detection device.
Further preferably, the portable terminal device includes a data adapter unit coupled between the data communication device and the connector. The data adapter unit has the power controlled by the output of the power-on detection device.
According to another aspect of the present invention, a portable terminal device includes a connector to be connected to a mobile telephone terminal device that provides a first signal changing the status of its output depending upon whether power is turned on or not, a power-on detection device connected to the connector, a mode switch circuit receiving the output of the power-on detection device and a predetermined mode specify signal at the inputs to output a mode signal, a power supply circuit under control of the mode signal, and a data communication device receiving power supply from the power supply circuit, and under control of the output of the power-on detection device.
Preferably, the data communication device includes a processor that activates system software when power supply from the power supply circuit is initiated. The system software activates communication software for data communication in response to the mode signal. The system software can also activate an application program that uses the communication software in response to the output of the power-on detection device.
Further preferably, the system software can execute an operation mode set application that specifies an operational mode. The operational mode set application provides a mode specify signal to the mode switch circuit.
The portable terminal device further includes a data adapter unit coupled between the data communication device and the connector. The data adapter unit has the power supply controlled by the output of the power-on detection device.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.